Contents

Prelude

For the past five years Balin and other Dwarves from Erebor had been exploring Moria after retaking and colonizing it. However on November 10th, 2994 Orcs surprise attacked the colonists in the Dimrill Dale; killing Lord Balin as he was looking into the Mirrormere, and despite being barred shut eventually took the East-gate, and First Hall from the Dwarves. [2]

Opposing Forces

The Dwarves' numbers are unknown other than they were not as many as the Orcs. There were at least a little over nine in number as Óin, Ori, Náli, Frár, Lóni and at least a little over four others were present.[2]
The Orcs were many though precise numbers are not given. It could have been as few as a hundred or many times that.

The Battle

Little is known as to how battle unfolded. However we can surmise that with the fall of the First Hall, all that stood before the Orcs was the Bridge of Khazad-dûm: the last difficult defensive structure in their path. On the other side the Dwarves mounted a final well positioned defense. The Orcs likely suffered heavy casualties trying to cross the bridge, as it was designed for enemies to have to march single file and totally exposed to the other side.
Despite this the Orcs eventually took the bridge and joined battle with the Dwarves in the hall. If taken literally it may have been that only three Dwarves (Lóni, Náli, and Frár) were killed in the ensuing brawl since Ori said in his account that they died bravely while the rest of them escaped to the Seventh Level. No matter the casualties numbers, the Dwarves retreated and the Orcs reclaimed the Hall. Initiating the beginning of the end of the Colony. [2]

Aftermath

Sometime after the battle, Óin was sent with over four others to see if survivors could escape out of the Doors of Durin. He was killed by the Watcher in the Water, and only four returned to the Chamber of Mazarbul after five days. It was their that the colonists made a last stand. Surrounded, extremely few, and with no hope of escape they perished.[2]